Desander



March 1, 1966 D. D. BROWN ETAL 3,237,777

DESANDER Filed June 19, 1962 2 Sheets-Sheet 1 INVENTORS: BELMONT D. BROWN WALTER H. J. LOWN o'scenszo, BY GEORGE W. LOWN, EXECUTOR ATT YS March 1, 1966 BROWN ET AL 3,237,777

DESANDER Filed June 19, 1962 2 Sheets-Sheet 2 INVENTORS DELMONT D. BROWN WALTER H. J. LOWN, DECEASED, BY GEORGE W. LOWN, EXECUTOR Lu-J5 104 .Q PM? ATT 'YS United States Patent 3,237,777 DESANDER Delmont D. Brown, 333 S. Main St North Baltimore,

Ohio, and Walter H. 3. Lawn, deceased, late of San Angelo, Tern, by George W. Lawn, executor, 2299 Live Oak, San Angelo, Tex.

Filed June 19, 1962, Ser. No. 203,657 3 Claims. (Cl. 21tl512) This invention, in general, relates to apparatus for removing abrasive particles such as sand, rock, grit and metal chips from a liquid in which the particles are suspended. The invention is concerned with improvements for increasing the useful life of such apparatus and component parts thereof.

Return drilling mud from holes drilled by the mud drilling method for oil, gas or water wells contains abrasive particles of sand, rock, grit and metal wearings or chips from the drill bit. These particles are highly abrasive and acidulous and cause excessive wear on pumps, drill bits and the like. The desander of this invention serves the purpose of removing these abrasive particles from a drilling mud so that the mud can be recirculated into the hole without harmful, highly abrasive effect on pumps, drill bits, etc. The cleaning of a drilling mud, however, is only one exemplary use for the apparatus of the invention. It may be used to clean any other abrasive slurry or semi-liquid mass.

The invention and the principles upon which the invention is based are exemplified in the embodiment of the invention illustrated in the drawings, wherein:

FIG. 1 is a top plan view of the desander;

FIG. 2 is a side elevation thereof;

FIG. 3 is an exploded view of a separator;

FIG. 4 is an assembly of desander components shown in FIG. 3; and

FIG. 5 is a fragmentary view in side elevation of another embodiment of the invention.

Referring to the drawings, the desander is mounted on a drag frame 1 comprising a pair of H-beams 2 cross braced by a pipe 3 at the end thereof. The space between H-beams is covered by a tread plate 4 supported on metal angle cross braces 5 extending between the P-bearns. A frame 6 of angle iron is mounted on the plate 4. The frame comprises bottom braces 7, upwardly and inwardly directed support legs 8, cross braces 9 and 10, and a rectangular frame top composed of angles 11, 12, 13 and 14. The frame supports three desanders 15, 16 and 17 mounted side-by-side on the frame.

Drilling mud is drawn by the centrifugal pump 18 through the pump inlet pipe 19 and is discharged through the pump outlet 20. The rotary impeller of pump 18 is driven by the drive shaft 21 journalled in the bearing 22 which is mounted on the plate 4 by the bearing support 23. The shaft 21 is coupled by coupling 24 to the output shaft 25 of a clutch 26 driven by an electric motor or an engine (not shown) on the frame 1.

The discharge outlet 26 of pump 15 is coupled to a vertical pipe 27, which, in turn, is coupled by flexible hose 23 to the vertical leg 29 of the desander intake manifold 30. The intake manifold 30 feeds the pumped fluid into the three desanders 15, 16 and 17 connected in parallel to the manifold 30.

The details of construction of the desanders 15, 16 and 17 is shown in FTGS. 3 and 4 wherein a desander is shown in exploded and in assembled detail. Fluid pumped into manifold 3t) is discharged into the three desanders through intake manifold discharge pipes 31, 32 and 33. The ends of the manifold pipe 30 are capped with caps 34 and 35. The ends of the pipes 31-33 are screw threaded, and one end of a coupler 36 is threaded on each discharge pipe. The coupler 36 is threaded at its other end to the reducing nipple 37. The nipple 37 is connected to the centrifuge head of the desander in a manner described hereafter.

The desander comprises a metal casting centrifuge head 83 having a cylindrical hollow head 39 with a rectangular, tangential inlet 40. At the bottom of the cylinder, there is a flange 41 containing bolt holes 42. The flange has diametrically opposite ears 44 with bolt holes for bolting the centrifuge heads to the frame pieces 9 and 10.

The rectangular inlet 40 has a front plate 43 with a rectangular opening 44'. A cover plate 45 with a threaded hole 46 is bolted on the front plate 43. The threaded hole 46 threadedly receives the threaded reduced end 47 of the reducing nipple 37.

The top 48 of the centrifuge head has an axially central opening 50 and bolt holes 42 The bolt holes 49 are used to bolt the flange 52 of the feed pipe 51 of take-off manifold 52 to the centrifuge head 38. The manifold 52 is capped at one end by cap 54 and is threaded at the other end 55 for coupling to discharge pipe.

The centrifuge head 38 is lined with a molded, abrasion resistant synthetic resin liner 56 of the same general shape as the centrifuge head 38. The liner 56 fits snugly inside the head 38 with the externally threaded sleeve 57 projecting through the hole 50 of head 38. The liner 56 is secured in the head 38 by threading a lock nut 58 on the sleeve 57 before the centrifuge head 33 is bolted to flange 52 with gasket 59 between the latter.

The liner 56 has a rectangular block 60, the front wall 61 of which has an axial inlet passage 62 into which extends the reduced end 47 of the nipple 37. The abrasive liquid is discharged from the nipple 37 tangentially against the inner face of the cylindrical wall 63 of the liner. The heavier abrasive material is thrown outwardly against the wall 63, and the liquid is discharged from the center of the liner through sleeve 57.

The heavier abrasive material falls by gravity and settles out of the swirling liquid in the cone segment. The cone segment comprises a metal cone housing 64 having a flange 65 with bolt holes 66 at its upper end and a smaller flange 67 with bolt holes 68 at its lower end. The metal cone housing 64 contains a cone-shaped, abrasion resistant synthetic resin liner 69 which has a flange 70 which is companion in size and shape to the flange 71 of the centrifuge head liner 56. The flange 7t rests on the flange 65 when the liner 69 is inserted in the cone housing 64, and the flange 71 abuts against flange 41 when the centrifuge head liner 56 is mounted on the head 38.

The desander is assembled by placing the liners 56 and 6? in their respective metal casings in the manner described. The centrifuge head 56 is mounted on the manifold 53 by bolts 72 extending through bolt holes 73 and 74 in the flange 52 and gasket 59, respectively, into the tapped holes 49 in the top 48 of the head 38. The conplings 36 and 37 of intake manifold 30 are connected to the head 38 as previously described.

The cone housing 64 is connected to the centrifuge head 38 by bolts 75 and nuts '76, the bolts extending through bolt holes 42 and 66 in the flanges 41 and 65, respectively. When the bolts 75 are drawn up tightly, the flanges 70 and '71 of the liners are pressed tightly together between the flanged bottom of the head casing 38 and the flanged top of the cone housing 64 to give a fluid-tight joint between the liners.

The outlet at the bottom of the desanders comprises a choke housing 77 removahly bolted to the bottom of the cone housing. The choke housing has a short, hollow, tapered section 78. The upper part of the choke housing 77 has a flange 80 having bolt holes 81. The choke housing 77 is removably mounted on the bottom of the cone 3 housing 64 by nuts and bolts 82, the latter extending through bolt holes 63 and 81 in the flanges 67 and 80,

espectively.

The choke section also has a liner of synthetic, abrasion resistant resin. This liner 83 is a molded, tapered piece with an upper, annular flange 86 which seats on the flange 80 of the choke housing 77. The liner comprises a hollow, tapered, upper section 84 and a lower, tubular section 79 forming the discharge tube for the desander. An annular recess 85 in the upper side of the choke liner is companion to the bottom wall of the cone liner 69 in size and shape so that the latter wall, which projects slightly beyond the lower end of flange 67, may be seated in the recess 85. Together, they form a fluid-tight joint when the bolts 82 are tightened.

An advantage in making the choke 77 and choke liner 83 separate from the cone housing 64 an cone liner 69 can be traced to the wear development in desanders from attrition by the removed abrasive particles. The greatest wear is at the choke area. When the abrasion resistant lining must be replaced, the small molding 83 need only be replaced instead of the entire cone liner, assuming the wear necessitating the liner replacement occurred primarily in the choke area. Often one cone lining 69 will outlast three or four choke linings 83. The savings in lining replacement costs are obvious. The detection of leaks in the liners due to wear or rupture is aided by providing small, spaced weep holes 87 in the walls of the cone housing 64. These holes allow fluid escaping from the liner to flow out of the metal housing so that the leakage in the liner is readily detected. Similar weep holes may be used in the head 38 and choke section 77, if desired.

In the modification illustrated in FIG. 5, the cone housing 64 is detachably connected to the choke sect-ion 77 by a clamp device instead of by bolts. The cone housing 64 contains abrasion-resistant resin cone liner 69, similar to the cone liner of FIGS. 3 and 4. The abrasionresistant resin choke liner 83 is similar to the choke liner of FIGS. 3 and 4. Where applicable, like numerals have been used in FIG. to designate like parts previously described in reference to FIGS. 3 and 4. The flange 67 of the cone housing has on one side a downwardly depending tab 90 with a horizontal slot therein. 'lwheslot receives the ear 91 on the flange 80 of the choke section 77.

In the illustrated embodiment of FIG. 5, the cone housing and choke section are locked together by replacing car 91 in the horizontal slot in the tab 90, after which the sections are locked together by the clamping device 93. The lower end of the cone liner is seated in the annular recess in the upper end of the choke liner to give a fluid-tight union by operation of the clamping device 93. The flange on the choke liner rests on the upper surface 92 of the choke housing flange 80.

The clamping device 93 comprises a plate 94 mounted on flange 67 diametrically opposite tab 90, on which plate is pivotally mounted a bar 95. The bar 95 carries a locking head 96 pivotally mounted at the end of the bar. The head 96 has a locking pin 97 and a handle 98. When the arm. 95 is swung downwardly so that locking pin 97 is below the U-shaped bar 99 mounted on the side of the choke section 77, the parts are locked together by pressing handle 98 past center toward the choke section whereby the locking pin 97 presses against the underside of bar 99 to clamp together therespective liners in choke section and the cone housing.

The molded liners 56, 69 and 83 are made of a suitable moldable, abrasion-resistant synthetic resin. The abrasion-resistant synthetic resin found to be most suitable for the molded liners is a polyalkylene ether polyurethane polymer. These polymers are obtained by reacting a polyalkylene ether glycol (preferably a polytetramethylene ether glycol) having a molecular weight of at least 750, an organic d-iisocyanate and a chain-extending compound containing active hydrogen atoms. The latter compound may be water or hydrogen sulfide or an organic compound containing active hydrogen atoms on two different atoms in the organic molecule.

The polyalkylene ether glycols are polyalkylene ethers containing terminal hydroxy groups. These compounds are ordinarily derived from the polymerization of cyclic ethers such as alkylene oxides or dioxblane or from the condensation of glycols. They are sometimes known as polyalkylene glycols, polyalkylene oxide glycols, polyglycols or polyoxyalkylene diols. They may be represented by the formula HO(RO),,H, in which R stands for an alkylene radical and n is an integer greater than 1. In the polyethers useful in this invention, n is sufliciently large that the polyalkylene ether glycol has a molecular weight of at least 750. Not all the alkylene radicals present need be the same. Polyglycols formed by the copolymerization of a mixture of different alkylene oxides or glycols may be used, or the polyglycols may be derived from a cyclic ether such as dioxolane, which results in a product having the formula HO (CH OC H O H The alkylene radicals may be straight-chain or may have a branched chain as in the compound known as polypropylene ether glycol.

Any of a wide variety of organic diisocyanates may be employed in the reaction, including aromatic, aliphatic and cycloaliphatic diisocyanates and combinations of these types. Representative compounds include 2,4-tolylene diisocyanate, rn-phenylene diisocyanate, 4-chloro-1,3- phenylene diisocyanate, 4,4-biphenylene diisocyanate, 1,5- naphthylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,6 hexamethylene diisocyanate, 1,10 decamethylene diisocyanate, 1,4 cyclohexylcne diisocyanate, 4,4- methylene-bis-(cyclohexyl isocyanate) and LS-tetrahydronaphthylene diisocyanate. Arylene diisocyanates, i.e., those in which each of the two isocyanate groups is attached directly to an aromatic ring, are preferred. In general, they react more rapidly with the polyalkylene ether glycols than do the alkylene diisocyanates. Compounds such as 2,4-tolylene diisocyanate in which the two isocyanate groups differ in reactivity are particularly desirable. The diisocyanates may contain other substituents, although those which are free from reactive groups other than the two isocyanate groups are ordinarily preferred. In the case of the aromatic compounds, the isocyanate groups may be attached either to the same or to different rings.

The chain-extender is usually water although other chain extenders of the type mentioned in US. Patent No. 2,929,800, may be used.

Another class of resins suitable for manufacture of the abrasion-resistant liners of the invention are the polyester urethane resins. These resins are produced by the reaction of organic diisocyanates with organic polyesters or organic polycarboxylic acids and polyhydric alcohols. Examples of said diisocyanates are hexamethylene diisocyanate and tolylene diisocyanate. The polycarboxylic acids may be adipic acid, phthalic acid, succinnic acid and the like. The polyhydric alcohols may be dihydric or trihydric alcohols such as ethylene glycol, diethylene glycol, butylene glycol-1,3, glycerol, trimethylolpropane and the like. The organic polyesters may be those prepared by condensation of the foregoing acids and alcohols or may be an alkyd resin. Furthermore, the resins may be produced from polyisocyanates or polythioisocyanates and amino alcohols and dicarboxy acids; glycols, diamines and dicarboxy acids; glycols, amino alcohols and dicarboxy acids; amino alcohols, diarnines and dicarboxy acids; amino acids, amino alcohols and dicarboxy acids; glycols, dicarboxy acids and hydroxycarboxy acids; or amino alcohols, dicarboxy acids and hydroxycarboxy acids. These resins are described in U.S. Patent 2,333,639, the disclosure of which is incorporated herein by reference.

The choke liner 83 in each embodiment is sufficiently elastic so that the tubular segment 79 can be compressed by a ring clamp of any suitable construction. The ring clamp 100 shown in FIGS. 4 and S is a metal band having a pair of cars 101 through which extend a threaded member, e.g., a bolt 102. The structure of the ring clamp may be like that of the usual hose clamps. Upon tightening the clamp 100, the tubular neck 79 is compressed radially inwardly to restrict the size of the cylindrical passage 104 through the neck 79. This arrangement may be used to adjust the dryness of the solids discharged from the passage 104 in the neck 79. If it is desired, for example, to decrease the amount of water discharged with the solids, this can be done by tightening clamp 100 so that the flow rate of solids from neck 79 is restricted sutficiently to provide a reduced moisture content in the discharged solids. By proper adjustment, the discharged solids may be substantially free from Water other than absorbed water or Water clinging to the surafces of the solid particles.

The foregoing embodiments exemplify the principles upon which the invention is founded. Other embodiments of the invention are readily derived by the application of these principles without departing from the spirit and scope of the invention.

The invention is hereby claimed as follows:

1. Apparatus for removing abrasive, solid particles from liquids which comprises a metal head casing, said head casing including a hollow, cylindrical portion and a rectangular, hollow extension projecting tangentially from said cylindrical portion and communicating at its inner end with said cylindrical portion, said cylindrical portion and said extension being open at the bottoms thereof, said cylindrical portion having a top wall with a central opening therein, said extension having a front wall with an opening therein, a removable, cylindrical liner of an abrasion-resistant synthetic resin mounted in said head casing, said liner being open at the bottom and having a top wall with a central opening therein, a rectangular block made of said synthetic resin and projecting tangentically from said cylindrical liner, said block being seated in said rectangular, hollow extension and having an axial passage for admitting a liquid under pressure tangentially against the inner side of the cylindrical wall of said liner, a plate removably mounted over said opening of said front wall of said hollow extension, said plate having a threaded hole aligned with said passage, a nipple having a threaded end threadedly received in said threaded hole, said nipple extending through said plate and into said axial passage, a cone housing positioned below said head casing, a removable cone liner of abrasion resistant synthetic resin in said cone housing with the upper edge of said cone liner in fluid-tight contact with the lower edge of the cylindrical Wall of said cylindrical liner, a flange on said head casing, a flange on the top of said cone housing, flanges on the contacting edges of said liners extending between the bottom of said head casing and the top of said cone housing, and bolts extending between said flanges on said casing and said housing for drawing the latter together and squeezing therebetween the flanges of said liners to pro vide a fluid-tight joint between said liners.

2. The apparatus of claim 1 wherein said liners are molded from polyalkylene ether polyurethane resin.

3. The combination of claim 1 wherein said liners are molded from a polyester urethane resin.

References Cited by the Examiner UNITED STATES PATENTS 2,772,860 12/ 1956 Nelson 220-63 2,816,658 12/1957 Braun et al 210-512 X 2,995,255 8/1961 Demeter 210512 3,021,307 2/1962 Csendes et al 26077 .5 3,036,996 5/ 1962 Kogen 26077.5 3,057,476 10/1962 Gilbert 210-512 X FOREIGN PATENTS 541,784 10/ 1955 Belgium. 712,792 7/ 1954 Great Britain.

REUBEN FRIEDMAN, Primary Examiner. HERBERT L. MARTIN, Examiner. 

1. APPARATUS FOR REMOVING ABRASIVE, SOLID PARTICLES FROM LIQUIDS WHICH COMPRISES A METAL HEAD CASING, SAID HEAD CASING INCLUDING A HOLLOW, CYLINDRICAL PORTION AND A RECTANGULA, HOLLOW EXTENSION PROJECTING TANGENTIALLY FROM SAID CYLINDRICAL PORTION AND COMMUNICATING AT ITS INNER END WITH SAID CYLINDRICAL PORTION, SAID CYLINDRICAL PORTION AND SAID EXTENSION BEING OPEN AT THE BOTTOMS THEREOF, SAID CYLINDRICAL PORTION HAVING A TOP WALL WITH A CENTRAL OPENING THEREIN, SAID EXTENSION HAVING A FRONT WALL WITH AN OPENING THEREON, A REMOVABLE, CYLINDRICAL LINER OF AN ABRASION-RESISTANT SYNTHETIC RESIN MOUNTED IN SAID HEAD CASING, SAID LINER BEING OPEN AT THE BOTTOM AND HAVING A TOP WALL WITH A CENTRAL OPENING THEREIN, A RECTANGULAR BLOCK MADE OF SAID SYNTHETIC RESIN AND PROJECTING TANGENTIALLY FROM SAID CYLINDRICAL LINER, SAID BLOCK BEING SEATED IN SAID RECTANGULAR, HOLLOW EXTENSION AND HAVING AN AXIAL PASSAGE FOR ADMITTING A LIQUID UNDER PRESSURE TANGENTIALLY AGAINST THE INNER SIDE OF THE CYLINDRICAL WALL OF SAID LINER, A PLATE REMOVABLY MOUNTED OVER SAID OPENING OF SAID FRONT WALL OF SAID HOLLOW EXTENSION, SAID PLATE HAVING A 